Research Description: Identifying, characterizing, and engineering natural products expands both our pool of potential new drugs and our knowledge of natureís biochemical repertoire. Ribosomally translated and post-translationally modified peptides (RiPPs), a class of natural products, are particularly amenable to discovery and structure-function studies because their peptide scaffolds are genetically encoded. After translation of these peptides, tailoring enzymes perform exotic modifications that are critical for bioactivity of the mature natural products. Many RiPPs and their modifications are too complex for industrial-scale organic synthesis, but some of the tailoring enzymes appear to exhibit relaxed substrate specificity, potentially allowing for the use of recombinant protein expression and enzymatic synthesis to produce libraries of engineered RiPPs. My work focuses on discovery of RiPPs with novel or challenging chemical modifications and mechanistic characterization of the tailoring enzymes involved in their biosynthesis.